@article{EspeRailaHenzeetal.2011,
  author    = {Espe, Katharina M. and Raila, Jens and Henze, Andrea and Krane, Vera and Schweigert, Florian J. and Hocher, Berthold and Wanner, Christoph and Drechsler, Christiane},
  title     = {Impact of vitamin A on clinical outcomes in haemodialysis patients},
  series = {Nephrology, dialysis, transplantation},
  volume    = {26},
  journal   = {Nephrology, dialysis, transplantation},
  number    = {12},
  publisher = {Oxford Univ. Press},
  address   = {Oxford},
  organization    = {German Diabetes \& Dialysis Study I},
  issn      = {0931-0509},
  doi       = {10.1093/ndt/gfr171},
  pages     = {4054 -- U583},
  year      = {2011},
  abstract  = {Background. Patients on maintenance haemodialysis treatment experience an excessive risk of cardiovascular disease and mortality. The vitamin A concentration is known to be higher in these patients compared to the general population where elevated vitamin A concentrations are associated with adverse outcome. The impact of vitamin A on morbidity and mortality in end-stage renal disease patients is controversial and is the topic of this study. Methods. We analysed plasma retinol and retinol-binding protein 4 (RBP4) in 1177 diabetic haemodialysis patients, who participated in the German Diabetes and Dialysis Study (median follow-up 4 years). By Cox regression analyses hazard ratios (HRs) were determined for pre-specified, adjudicated end points according to baseline concentrations. Results. Patients had a mean age of 66 +/- 8 years, mean retinol and RBP4 concentrations of 3.28 (0.71-7.44) and 4.02 (1.28-10.1) mu mol/L, respectively. Patients with retinol concentrations in the first quartile (<2.6 mu mol/L) had an almost 2-fold increased risk of all-cause mortality compared to patients of the fourth quartile [>3.9 mu mol/L; HR 1.81, 95\% confidence interval (CI) 1.43-2.30]. There was a strong association between low retinol and the risk of sudden cardiac death (SCD, HR 2.22, 95\% CI 1.41-3.50) and fatal infection (HR 2.19, 95\% CI 1.26-3.82). Patients with RBP4 concentrations in the lowest quartile (<3.0 mu mol/L) were more likely to die of any cause (HR 1.43, 95\% CI 1.14-1.80), experience SCD (HR 1.97, 95\% CI 1.28-3.03) and cardiovascular events (HR 1.43, 95\% CI 1.10-1.85). Conclusion. This large cohort study shows a strong association of low retinol and RBP4 concentrations with SCD and all-cause mortality in diabetic haemodialysis patients.},
  language  = {en}
}
@article{HenzeRailaKempfetal.2011,
  author    = {Henze, Andrea and Raila, Jens and Kempf, Caroline and Reinke, Petra and Sefrin, Anett and Querfeld, Uwe and Schweigert, Florian J.},
  title     = {Vitamin A metabolism is changed in donors after living-kidney transplantation an observational study},
  series = {Lipids in health and disease},
  volume    = {10},
  journal   = {Lipids in health and disease},
  number    = {23},
  publisher = {BioMed Central},
  address   = {London},
  issn      = {1476-511X},
  doi       = {10.1186/1476-511X-10-231},
  pages     = {7},
  year      = {2011},
  abstract  = {Background: The kidneys are essential for the metabolism of vitamin A (retinol) and its transport proteins retinol-binding protein 4 (RBP4) and transthyretin. Little is known about changes in serum concentration after living donor kidney transplantation (LDKT) as a consequence of unilateral nephrectomy; although an association of these parameters with the risk of cardiovascular diseases and insulin resistance has been suggested. Therefore we analyzed the concentration of retinol, RBP4, apoRBP4 and transthyretin in serum of 20 living-kidney donors and respective recipients at baseline as well as 6 weeks and 6 months after LDKT. Results: As a consequence of LDKT, the kidney function of recipients was improved while the kidney function of donors was moderately reduced within 6 weeks after LDKT. With regard to vitamin A metabolism, the recipients revealed higher levels of retinol, RBP4, transthyretin and apoRBP4 before LDKT in comparison to donors. After LDKT, the levels of all four parameters decreased in serum of the recipients, while retinol, RBP4 as well as apoRBP4 serum levels of donors increased and remained increased during the follow-up period of 6 months. Conclusion: LDKT is generally regarded as beneficial for allograft recipients and not particularly detrimental for the donors. However, it could be demonstrated in this study that a moderate reduction of kidney function by unilateral nephrectomy, resulted in an imbalance of components of vitamin A metabolism with a significant increase of retinol and RBP4 and apoRBP4 concentration in serum of donors.},
  language  = {en}
}
@article{BechirSchellingKraemeretal.2012,
  author    = {Bechir, Mahamat and Schelling, E. and Kr{\"a}mer, K. and Schweigert, Florian J. and Bonfoh, Bassirou and Crump, L. and Tanner, M. and Zinsstag, J.},
  title     = {Retinol assessment among women and children in sahelian mobile pastoralists},
  series = {EcoHealth : conservation medicine, human health, ecosystem sustainability},
  volume    = {9},
  journal   = {EcoHealth : conservation medicine, human health, ecosystem sustainability},
  number    = {2},
  publisher = {Springer},
  address   = {New York},
  issn      = {1612-9202},
  doi       = {10.1007/s10393-012-0781-7},
  pages     = {113 -- 121},
  year      = {2012},
  abstract  = {Micronutrient deficiencies are widespread in developing countries, particularly in remote communities such as mobile pastoralists. The nutritional and vitamin A status of this population is not well-documented in Chad. This study assessed serum retinol levels among women and children under five-year-old in nomadic and semi-nomadic pastoralist and rural-settled communities, who are similarly exposed to risk factors such as gastrointestinal parasitic infection, anaemia and emaciation. The novel method of portable fluorometry was used for the first time to measure beta-carotene and retinol levels in a pastoral nomadic area. Moderate level blood retinol deficiency (< 0.7 mu mol/L) was observed in 5\% (CI 1-11) of nomadic, 29\% (CI 13-45) of semi-nomadic and 22\% (CI 8-35) of sedentary women. In children, 1\% (CI 0.1-4), 17\% (CI 9-25) and 28\% (CI 18-39), respectively, had moderate level blood retinol deficiency. In nomadic communities, women and children had blood retinol levels close to normal. Deficiency of retinol was strongly linked with lifestyle (nomadic, semi-nomadic and settled) among women and lifestyle and age among children. The results support an ecological linkage between human retinol levels and livestock milk retinol. This study shows the feasibility of portable retinol and beta-carotene measurement in human blood as well as human and animal milk under remote field conditions, but the approach requires further validation.},
  language  = {en}
}
@article{MuellerRailaAltenkampetal.2012,
  author    = {Mueller, K. and Raila, Jens and Altenkamp, Rainer and Schmidt, D. and Dietrich, R. and Hurtienne, Andrea and Wink, M. and Krone, O. and Brunnberg, Leo and Schweigert, Florian J.},
  title     = {Concentrations of retinol, 3,4-didehydroretinol, and retinyl esters in plasma of free-ranging birds of prey},
  series = {Journal of animal physiology and animal nutrition},
  volume    = {96},
  journal   = {Journal of animal physiology and animal nutrition},
  number    = {6},
  publisher = {Wiley-Blackwell},
  address   = {Hoboken},
  issn      = {0931-2439},
  doi       = {10.1111/j.1439-0396.2011.01219.x},
  pages     = {1044 -- 1053},
  year      = {2012},
  abstract  = {This study investigated vitamin A compounds in the plasma of healthy free-ranging Central European raptors with different feeding strategies. Plasma samples of nestlings of white-tailed sea eagle [white-tailed sea eagle (WTSE), Haliaeetus albicilla) (n = 32), osprey (Pandion haliaetus) (n = 39), northern goshawk (Accipiter gentilis) (n = 25), common buzzard (Buteo buteo) (n = 31), and honey buzzard (Pernis apivorus) (n = 18) and adults of WTSE (n = 10), osprey (n = 31), and northern goshawk (n = 45) were investigated with reversed-phase-high-performance liquid chromatography (RP-HPLC). In WTSE, northern goshawks and common buzzards retinol were the main plasma component of vitamin A, whilst in ospreys and honey buzzards, 3,4-didehydroretinol predominated. The median of the retinol plasma concentration in the nestlings group ranged from 0.12 to 3.80 mu M and in the adult group from 0.15 to 6.13 mu M. Median plasma concentrations of 3,4-didehydroretinol in nestlings ranged from 0.06 to 3.55 mu M. In adults, northern goshawks had the lowest plasma concentration of 3,4-didehydroretinol followed by WTSE and ospreys. The plasma of all investigated species contained retinyl esters (palmitate, oleate, and stearate). The results show considerable species-specific differences in the vitamin A plasma concentrations that might be caused by different nutrition strategies.},
  language  = {en}
}